Last of the U-Boots

Ducimus · 12-23-06, 09:54 PM

Quote:

Originally Posted by Letum

It's not like the VII boats where really built to last in the first place!

I read somewhere that VII boats were single hulled, not a true double hull. That always stuck out to me for some reason. Personnaly if i had to be on a submarine, id feel better on one with a full double hull that encloses the pressure hull.

CCIP · 12-24-06, 12:18 AM

Hmm, I wonder what's meant by that... I always thought the II was a single hull, while the VII was a double hull. Looking at diagrams... well, I'm not sure actually

Whatever it was, it certainly was a hell of a lot tougher than any other single-hull boat that I know of.

Letum · 12-24-06, 12:35 AM

Quote:

Originally Posted by CCIP

Hmm, I wonder what's meant by that... I always thought the II was a single hull, while the VII was a double hull. Looking at diagrams... well, I'm not sure actually

Whatever it was, it certainly was a hell of a lot tougher than any other single-hull boat that I know of.

The VII is a pressure hull surrounded by fuel tanks, ballast tanks and a non water tight skin. The skin just covers external components and pipes, it also gives the boat a more streamlined shape. It is not a second hull because it is not at all watertight.
The holes all along the u-boats skin are to let water in to the cavity between the skin and the pressure hull so that the boat can dive quickly. If you poke a stick through the holes you can knock on the pressure hull.
It all depends ion how you define a hull really, but I think the VII's outer steel is more of a skin than a hull.

Ducimus · 12-24-06, 12:57 AM

Well technically i think both the IX and VII are double hull.

Double hull meaning, pressure hull with an exterior casing that surrounds the pressurehull that is free flooding. Also known as the subs super structure by some. The super structures primary job, at least to my understanding, is to form a protective layer around the submarine and it's components that reside outside of the pressure hull. (Air flasks, fuel tanks, ballast tanks, etc etc at nausem)

Now the biggest difference that im aware of between the two uboats in question is that the type 9 has a full superstructure, where as the type7 has just a partial one. This is why on the type7, you can see the saddle tanks, where as the type9, which also has saddle tanks, you can't see them because its completely covered by the outer hull. So im guessing up top, along the main deck both subs have equal double hulled protection, but after that, things sort of thin out. It give's the impression that the type 9's pressure hull might be more protected then the type7's, but i think the reality is, the outterhull wasnt really designed as armor plating :rotfl:

Another intresting note is how later in the war, you had modifications done to the type9 that cut down the main deck/outter hull.. Air would get trapped inside the boats outter hull, which slowed down its dive time. The type 7, never had this problem.

12-24-06, 12:18 AM	#2
CCIP Navy Seal Join Date: Apr 2005 Location: Waterloo, Canada Posts: 8,700 Downloads: 29 Uploads: 2	Hmm, I wonder what's meant by that... I always thought the II was a single hull, while the VII was a double hull. Looking at diagrams... well, I'm not sure actually Whatever it was, it certainly was a hell of a lot tougher than any other single-hull boat that I know of. __________________ There are only forty people in the world and five of them are hamburgers. -Don Van Vliet (aka Captain Beefheart)

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12-24-06, 12:57 AM	#4
Ducimus Rear Admiral Join Date: May 2005 Posts: 12,987 Downloads: 67 Uploads: 2	Well technically i think both the IX and VII are double hull. Double hull meaning, pressure hull with an exterior casing that surrounds the pressurehull that is free flooding. Also known as the subs super structure by some. The super structures primary job, at least to my understanding, is to form a protective layer around the submarine and it's components that reside outside of the pressure hull. (Air flasks, fuel tanks, ballast tanks, etc etc at nausem) Now the biggest difference that im aware of between the two uboats in question is that the type 9 has a full superstructure, where as the type7 has just a partial one. This is why on the type7, you can see the saddle tanks, where as the type9, which also has saddle tanks, you can't see them because its completely covered by the outer hull. So im guessing up top, along the main deck both subs have equal double hulled protection, but after that, things sort of thin out. It give's the impression that the type 9's pressure hull might be more protected then the type7's, but i think the reality is, the outterhull wasnt really designed as armor plating :rotfl: Another intresting note is how later in the war, you had modifications done to the type9 that cut down the main deck/outter hull.. Air would get trapped inside the boats outter hull, which slowed down its dive time. The type 7, never had this problem.